Police said new information received in the past few days led them to charge a 25-year-old man with first-degree murder in the stabbing deaths of Laura Young and George Washington Burnett.
But Staff Sgt. Steve Hrab of Hamilton police revealed few details on the investigation and wouldn't comment on how the accused knew the pair or whether the attacks were random.
Young's body was found behind a building on Cathcart Street in Hamilton on Feb. 16.
Nearly seven months later, Burnett was found on Sept. 6 in the Stirton Avenue home where he lived alone. He was 83.
Police arrested Loujack Nougues Cafe of no fixed address on Friday.
Officers also charged him with attempted murder in three separate stabbings between early November and mid-December.
He was remanded into custody after a brief appearance in court Saturday. His next appearance is scheduled for Wednesday.